1. Technical Field
The present invention relates to an oil-cooled engine and more particularly concerns an oil-cooled engine capable of reducing the oil-consumption amount.
2. Background of the Art
A conventional example of those oil-cooled engines comprises a cylinder along a lateral and peripheral wall of which an oil-cooling jacket is formed as well as the present invention. An oil-return passage and a push-rod chamber are formed along a lateral and peripheral wall of the oil-cooling jacket disposed, opposite to the cylinder lateral and peripheral wall with the oil-cooling jacket interposed between the cylinder lateral and peripheral wall and the oil-cooling jacket lateral and peripheral wall. The oil-return passage and the push-rod chamber are directed in an up and down direction so that an oil pump feeds engine oil under pressure, which is then returned from the oil-return passage into a crank case. The push-rod chamber has a bottom wall which is opened to provide a tappet-guide hole into which a tappet is internally fitted and below which a valve-operating cam shaft spans in a front and rear direction and has a cam on which a tappet is placed (for example, see Patent Literature 1).
However, in the conventional oil-cooled engine, the push-rod chamber has the bottom wall opened to provide an oil outlet for the oil-return passage, which is located just above a fuel injection cam immediately laterally and slantly downwards of a mid side portion of the cylinder lateral and peripheral wall and therefore causes problems.
[Patent Literature 1]
    Patent Application Laid-Open No. 63-183214 (see FIG. 4)